European Union source: Wikipedia SignedIn forceDocumentSignedIn forceDocument 1948 1948 Brussels Treaty Brussels Treaty 1951 1952 Paris Treaty Paris Treaty 1954 1955 Modified Brussels Treaty Modified Brussels Treaty 1957 1958 Rome treaties Rome treaties 1965 1967 Merger Treaty Merger Treaty 1975 N/A European Council conclusion European Council conclusion 1985 1985 Scheng en Treaty Scheng en Treaty 1986 1987 Single European Act Single European Act 1992 1993 Maastricht Treaty Maastricht Treaty 1997 1999 Amsterdam Treaty Amsterdam Treaty 2001 2003 Nice Treaty Nice Treaty 20072009Lisbon Treaty20072009Lisbon Treaty